San Onofre reactor restart hits more snags

SAN ONOFRE  Problems continue to crop up at the San Onofre nuclear power plant’s Unit 2 reactor, which operators wanted to restart in January after it was shut down for three months while two massive steam generators were replaced and the nuclear fuel restored.

The reactor remains idle nearly six months after that job began in late September.

Officials with Southern California Edison, which operates San Onofre’s two reactors in northern San Diego County, say the delay has been caused by several unexpected issues connected with the steam-generator replacement, including the discovery of a bubble in the weld that joined one of the generators and the reactor. That weld was redone.

Other less-serious maintenance chores that were scheduled during the outage have taken longer than expected, causing delays.

“We have an obligation not only to the company but to the public that lives near the plant to make sure that when Unit 2 is brought back, it’s in the best condition that we can make and we have a very safe operation,” said Ross Ridenoure, the plant’s chief nuclear officer.

The Nuclear Regulatory Commission also issued its annual report card on the plant last week. The NRC assigned an extra resident inspector at the plant last year, saying it needed to improve its safety culture. It also issued a separate report last week saying that some workers fear retaliation if they report nuclear safety violations to their superiors or the NRC.

However, inspectors said they’re not satisfied that Edison has corrected institutional problems that caused a failure to detect a faulty battery connection at Unit 2 for four years.

Ridenoure said he was disappointed that the NRC hasn’t seen fit to upgrade its rating of Unit 2, but “our improvement efforts are gaining traction.”

“What we’re seeing is the majority of plant personnel understand that our performance needs to improve at an accelerated pace,” Ridenoure said.

The two reactors combined generate 2,200 megawatts, enough to supply about 1.5 million homes. Twenty percent of the power goes to San Diego Gas & Electric Co. Edison must buy replacement energy when a reactor is out of service.

A messy mishap that occurred last week delayed the restart by a few days. It happened during a test of Unit 2’s 160-foot-tall dome.

Workers had cut a hole into the dome’s 4-foot-thick concrete wall last year to remove the old generators and install the new ones, then patched it.

Before restarting the reactor, Edison had to prove the building could contain any possible radiation leak, and the way to do that is to pump air under pressure into the massive building.

That air is filtered through a drying agent, a powdery chemical similar to that found in tiny packets in boxes of new shoes.

According to San Onofre and NRC officials, the canisters holding the chemicals burst at the test’s end, blowing hundreds of pounds of the powder throughout the building and covering surfaces with a fine white dust.

Ridenoure said the chemical isn’t hazardous, but it’s messy.

“It did cause a few days of delay because clearly, we don’t want that desiccant power anywhere inside the containment on any of the equipment or the horizontal surfaces,” Ridenoure said.

Victor Dricks, an NRC spokesman, said such mishaps don’t threaten the public.

“We have confidence they can operate the plant safely,” Dricks said.

Edison officials didn’t say precisely when Unit 2 will return to service, but said it will be soon.

A public meeting to discuss the NRC’s safety report is tentatively scheduled for March 24.